The interconnection of semiconductor devices has parasitic inductance, and when a semiconductor element is switching, an induced voltage is generated represented by the integral of the parasitic inductance and the current changing rate during switching (di/dt). Therefore, a direct current voltage of a power converter circuit and the induced voltage are applied to the semiconductor element. When a large voltage that is the sum of the direct current voltage and the induced voltage applied to the semiconductor element exceeds the breakdown voltage of the semiconductor element, there is a possibility of breakdown of the semiconductor element. In semiconductor devices, it is important to minimize parasitic inductance as much as possible in order to increase the reliability.